Field of the Invention
The present invention relates to a steering wheel of a vehicle equipped with an airbag module fixed to a steering wheel body with hooks inserted into holes and supported by engaging members.
Description of the Related Art
Steering wheels are known that are equipped with airbag modules attached to bosses (boss cores) serving as support members composing steering wheel bodies. An airbag module includes a folded airbag, an inflator for supplying gas to the airbag, a base plate to which the airbag and the inflator is attached, and a cover connected to the base plate to cover the airbag and the inflator.
JP 2011-148478 discloses an airbag module attached to a boss with a single operation. In particular, the airbag module includes a case having a base plate provided with three penetration openings on both right and left sides and on the bottom side to which snap-lock springs (wires) serving as U-shaped engaging members are attached. The airbag module is fixed to the boss of a steering wheel body such that three hooks serving as engaged members provided in the boss of the steering wheel body are inserted into the penetration openings so as to be engaged with the snap-lock springs.
The airbag module is attached to the boss with a single operation such that the airbag module is positioned in the boss in the front-rear direction (in the thickness direction of the steering wheel) due to the engagement between the hooks and the snap-lock springs. However, the airbag module and the boss cannot be positioned accurately in the top-bottom and right-left directions (in the diameter directions of the steering wheel) only by the engagement between the hooks and the snap-lock springs. In order to accurately position the airbag module in the boss in the top-bottom and right-left directions, a plurality of (a pair of) positioning pins (locator pins) are further provided in the airbag module, in addition to the hooks. Each positioning pin is provided, at the circumferential surface, with a plurality of flexible projecting claws which are flexibly brought into contact with the inner surfaces of openings provided in the boss (refer to pages 5 to 8, and FIG. 2 of JP 2011-148478).
However, such positioning pins may fail to position the airbag module in the boss accurately because the flexible claw located on the lowest side (at the six o'clock position) when the pin is in a laid state may be weighed down with the own weight of the airbag module. Thus, it is desirable to improve positioning performance of an airbag module in a weighing direction with high accuracy.